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1.
Front Immunol ; 15: 1426795, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39108267

RESUMEN

B cells surveil the body for foreign matter using their surface-expressed B cell antigen receptor (BCR), a tetrameric complex comprising a membrane-tethered antibody (mIg) that binds antigens and a signaling dimer (CD79AB) that conveys this interaction to the B cell. Recent cryogenic electron microscopy (cryo-EM) structures of IgM and IgG isotype BCRs provide the first complete views of their architecture, revealing that the largest interaction surfaces between the mIg and CD79AB are in their transmembrane domains (TMDs). These structures support decades of biochemical work interrogating the requirements for assembly of a functional BCR and provide the basis for explaining the effects of mutations. Here we report a focused saturating mutagenesis to comprehensively characterize the nature of the interactions in the mIg TMD that are required for BCR surface expression. We examined the effects of 600 single-amino-acid changes simultaneously in a pooled competition assay and quantified their effects by next-generation sequencing. Our deep mutational scanning results reflect a feature-rich TMD sequence, with some positions completely intolerant to mutation and others requiring specific biochemical properties such as charge, polarity or hydrophobicity, emphasizing the high value of saturating mutagenesis over, for example, alanine scanning. The data agree closely with published mutagenesis and the cryo-EM structures, while also highlighting several positions and surfaces that have not previously been characterized or have effects that are difficult to rationalize purely based on structure. This unbiased and complete mutagenesis dataset serves as a reference and framework for informed hypothesis testing, design of therapeutics to regulate BCR surface expression and to annotate patient mutations.


Asunto(s)
Receptores de Antígenos de Linfocitos B , Receptores de Antígenos de Linfocitos B/genética , Receptores de Antígenos de Linfocitos B/inmunología , Receptores de Antígenos de Linfocitos B/metabolismo , Humanos , Mutación , Animales , Linfocitos B/inmunología , Linfocitos B/metabolismo , Antígenos CD79/genética , Antígenos CD79/metabolismo , Antígenos CD79/inmunología , Membrana Celular/metabolismo , Ratones
3.
Blood Cancer Discov ; 5(5): 331-352, 2024 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-38630892

RESUMEN

Pathomechanisms that activate oncogenic B-cell receptor (BCR) signaling in diffuse large B-cell lymphoma (DLBCL) are largely unknown. Kelch-like family member 6 (KLHL6) encoding a substrate-adapter for Cullin-3-RING E3 ubiquitin ligase with poorly established targets is recurrently mutated in DLBCL. By applying high-throughput protein interactome screens and functional characterization, we discovered that KLHL6 regulates BCR by targeting its signaling subunits CD79A and CD79B. Loss of physiologic KLHL6 expression pattern was frequent among the MCD/C5-like activated B-cell DLBCLs and was associated with higher CD79B levels and dismal outcome. Mutations in the bric-a-brac tramtrack broad domain of KLHL6 disrupted its localization and heterodimerization and increased surface BCR levels and signaling, whereas Kelch domain mutants had the opposite effect. Malfunctions of KLHL6 mutants extended beyond proximal BCR signaling with distinct phenotypes from KLHL6 silencing. Collectively, our findings uncover how recurrent mutations in KLHL6 alter BCR signaling and induce actionable phenotypic characteristics in DLBCL. Significance: Oncogenic BCR signaling sustains DLBCL cells. We discovered that Cullin-3-RING E3 ubiquitin ligase substrate-adapter KLHL6 targets BCR heterodimer (CD79A/CD79B) for ubiquitin-mediated degradation. Recurrent somatic mutations in the KLHL6 gene cause corrupt BCR signaling by disrupting surface BCR homeostasis. Loss of KLHL6 expression and mutant-induced phenotypes associate with targetable disease characteristics in B-cell lymphoma. See related commentary by Leveille et al. See related commentary by Corcoran et al.


Asunto(s)
Proteínas Adaptadoras Transductoras de Señales , Antígenos CD79 , Linfoma de Células B Grandes Difuso , Receptores de Antígenos de Linfocitos B , Transducción de Señal , Humanos , Receptores de Antígenos de Linfocitos B/metabolismo , Receptores de Antígenos de Linfocitos B/genética , Proteínas Adaptadoras Transductoras de Señales/genética , Proteínas Adaptadoras Transductoras de Señales/metabolismo , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/metabolismo , Linfoma de Células B Grandes Difuso/patología , Antígenos CD79/genética , Antígenos CD79/metabolismo , Proteínas de Microfilamentos/genética , Proteínas de Microfilamentos/metabolismo , Mutación , Línea Celular Tumoral , Proteínas Portadoras
4.
Surv Ophthalmol ; 69(3): 456-464, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38163550

RESUMEN

Primary vitreoretinal lymphoma is a potentially aggressive intraocular malignancy with poor systemic prognosis and sometimes significant diagnostic delays as it may masquerade as chronic uveitis. Despite the variety of diagnostic techniques, it is unclear which modality is most accurate in the diagnosis of PVRL. A systematic literature search was conducted on Ovid MEDLINE, EMBASE and the Cochrane Controlled Register of Trials for studies published between January, 2000, and June, 2023. Randomized controlled trials (RCTs) reporting on the following diagnostic tools used to diagnose patients with PVRL were included: cytology, flow cytometry, MYD88 L265P mutation, CD79B mutation, interleukin 10/interleukin-6 (IL-10/IL-6) ratio, polymerase chain reaction (PCR) for monoclonal immunoglobulin heavy chain (IgH) and immunoglobulin kappa light chain (IgK) rearrangements, and imaging findings. The aggregated sensitivity of each diagnostic modality was reported and compared using the chi-squared (χ2) test. A total of 662 eyes from 29 retrospective studies reporting on patients diagnosed with PVRL were included. An IL-10/IL-6 ratio greater than 1 had the highest sensitivity (89.39%, n = 278/311 eyes, n = 16 studies) for PVRL, where the sensitivity was not significantly different when only vitreous samples were drawn (88.89%, n = 232/261 eyes, n = 13 studies) compared to aqueous samples (83.33%, n = 20/24, n = 2) (p = 0.42). Flow cytometry of vitreous samples gave a positive result in 66/75 eyes (88.00%, n = 6 studies) with PVRL, and monoclonal IgH rearrangements on PCR gave a positive result in 354/416 eyes (85.10%, n = 20 studies) with PVRL. MYD88 L265P and CD79B mutation analysis performed poorly, yielding a positive result in 63/90 eyes (70.00%, n = 8 studies) with PVRL, and 20/57 eyes (35.09%, n = 4 studies) with PVRL, respectively. Overall, our systematic review found that an IL-10/IL-6 ratio greater or equal to one may provide the highest sensitivity in identifying patients with PVRL. Future studies are needed to employ multiple diagnostic tools to aid in the detection of PVRL and to further establish nuanced guidelines when determining the optimal diagnostic tool to use in diverse patient populations.


Asunto(s)
Neoplasias de la Retina , Cuerpo Vítreo , Humanos , Neoplasias de la Retina/diagnóstico , Cuerpo Vítreo/patología , Cuerpo Vítreo/metabolismo , Interleucina-10/metabolismo , Linfoma Intraocular/diagnóstico , Linfoma Intraocular/metabolismo , Linfoma Intraocular/genética , Citometría de Flujo , Interleucina-6/metabolismo , Factor 88 de Diferenciación Mieloide/genética , Técnicas de Diagnóstico Oftalmológico , Biomarcadores de Tumor , Antígenos CD79/metabolismo , Reacción en Cadena de la Polimerasa/métodos
5.
Clin Lymphoma Myeloma Leuk ; 22(12): e1051-e1058.e1, 2022 12.
Artículo en Inglés | MEDLINE | ID: mdl-36182550

RESUMEN

INTRODUCTION: Previous studies have shown that diffuse large B-cell lymphoma (DLBCL) subtype with both B-cell antigen receptor complex-associated protein beta chain (CD79B) and myeloid differentiation primary response 88 mutations (MYD88) had inferior outcome under standard immunochemotherapy. However, the prognostic significance of CD79B alone in DLBCL has not been fully elucidated. We conducted a meta-analysis to investigate the role of CD79B mutation on overall survival (OS) in patients with DLBCL. METHODS: We performed literature search in PubMed and Embase databases and followed PRISMA guidelines to select publications for analysis. The primary and secondary outcome was OS and progression-free survival (PFS) respectively. Hazard ratio (HR) for OS/PFS in CD79B mutant group with that in wild-type group in R-chemotherapy patients was either estimated using Cox proportional hazard model from the studies with individual participant level data or extracted from the original publication with aggregated results. RESULTS: Nine eligible studies with survival information according to CD79B mutation status were included in this meta-analysis. The pooled hazard ratio for OS was 1.38 (95% CI, 1.13-1.70; p = 0.0021) for CD79B mutation, providing evidence that CD79B mutation was unfavorable prognostic factor for survival in DLBCL patients treated with immunochemotherapy. We identified the inferior prognostic impact of CD79B mutation was independent from well-established prognostic model in DLBCL, International Prognostic Index. The predictive power of CD79B mutation was stronger than that of MYD88 mutation. CONCLUSION: This meta-analysis revealed that CD79B mutation could be a key biomarker for DLBCL disease progression and future mechanism-based target therapy in DLBCL needs to be studied.


Asunto(s)
Linfoma de Células B Grandes Difuso , Factor 88 de Diferenciación Mieloide , Humanos , Pronóstico , Factor 88 de Diferenciación Mieloide/genética , Linfoma de Células B Grandes Difuso/diagnóstico , Linfoma de Células B Grandes Difuso/tratamiento farmacológico , Linfoma de Células B Grandes Difuso/genética , Mutación , Inmunoterapia , Antígenos CD79/genética , Antígenos CD79/metabolismo
6.
Eur J Immunol ; 52(8): 1350-1361, 2022 08.
Artículo en Inglés | MEDLINE | ID: mdl-35554927

RESUMEN

The GC reaction results in the selection of B cells acquiring effector Ig secreting ability by progressing toward plasmablastic differentiation. This transition is associated with exclusion from the GC microenvironment. The aberrant expansion of plasmablastic elements within the GC fringes configures an atypical condition, the biological characteristics of which have not been defined yet. We investigated the in situ immunophenotypical and transcriptional characteristics of a nonclonal germinotropic expansion of plasmablastic elements (GEx) occurring in the tonsil of a young patient. Compared to neighboring GC and perifollicular regions, the GEx showed a distinctive signature featuring key regulators of plasmacytic differentiation, cytokine signaling, and cell metabolism. The GEx signature was tested in the setting of diffuse large B-cell lymphoma (DLBCL) as a prototypical model of lymphomagenesis encompassing transformation at different stages of GC and post-GC functional differentiation. The signature outlined DLBCL clusters with different immune microenvironment composition and enrichment in genetic subtypes. This report represents the first insight into the transcriptional features of a germinotropic plasmablastic burst, shedding light into the molecular hallmarks of B cells undergoing plasmablastic differentiation and aberrant expansion within the noncanonical setting of the GC microenvironment.


Asunto(s)
Linfoma de Células B Grandes Difuso , Factor 88 de Diferenciación Mieloide , Antígenos CD79/genética , Antígenos CD79/metabolismo , Centro Germinal/metabolismo , Humanos , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/metabolismo , Linfoma de Células B Grandes Difuso/patología , Factor 88 de Diferenciación Mieloide/genética , Factor 88 de Diferenciación Mieloide/metabolismo , Células Plasmáticas/metabolismo , Transcriptoma , Microambiente Tumoral/genética
7.
Int Immunopharmacol ; 101(Pt B): 108343, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-34781122

RESUMEN

B cell-targeted therapies have evolved as established therapies for systemic lupus erythematosus (SLE); however, existing approaches still do not thoroughly satisfy clinical requirements due to limited efficacy against memory B cells, autoantibody-producing plasmablasts and disease heterogeneity. To provide a new treatment option for SLE, we created a novel anti-Igß antibody with enhanced affinity for Fc gamma receptor (FcγR) IIB called ASP2713. ASP2713 cross-reacted with both human and cynomolgus monkey Igß and showed increased binding affinity for human and monkey FcγRIIB compared to native human IgG1. This binding property allows dominant B cell binding and induction of intrinsic negative feedback signals. In human B cells, ASP2713 significantly and concentration-dependently induced FcγRIIB ITIM phosphorylation, while suppressing proliferation under B cell receptor stimulation. This pharmacological effect was also confirmed in in vitro B cell proliferation and antibody production assays using peripheral B cells isolated from patients with SLE. In a cynomolgus monkey tetanus toxoid-induced antibody production model, ASP2713 almost completely inhibited the increase in antigen-specific antibodies with superior efficacy to rituximab. Additionally, ASP2713 significantly suppressed recall antibody production in response to secondary tetanus toxoid immunization, indicating the memory B cell- and plasmablast-targeting potential of ASP2713. Our results suggest that ASP2713 may have therapeutic potential as a treatment for SLE, where B cells play a pathogenic role.


Asunto(s)
Anticuerpos Biespecíficos/metabolismo , Anticuerpos Monoclonales/metabolismo , Anticuerpos Monoclonales/uso terapéutico , Subgrupos de Linfocitos B/inmunología , Antígenos CD79/metabolismo , Lupus Eritematoso Sistémico/terapia , Receptores de IgG/metabolismo , Animales , Anticuerpos Biespecíficos/uso terapéutico , Proliferación Celular , Células Cultivadas , Humanos , Tolerancia Inmunológica , Inmunoterapia/métodos , Lupus Eritematoso Sistémico/inmunología , Activación de Linfocitos , Macaca fascicularis , Unión Proteica
8.
Sci Rep ; 11(1): 21220, 2021 10 27.
Artículo en Inglés | MEDLINE | ID: mdl-34707156

RESUMEN

Epstein-Barr virus (EBV) is an oncogenic herpesvirus implicated in the pathogenesis of several malignant and non-malignant conditions. However, a number of fundamental aspects about the biology of EBV and the mechanism(s) by which this virus induces pathology remain unknown. One major obstacle has been the lack of a suitable animal model for EBV infection. In this study, using our recently established rabbit model of EBV infection, we examined the early events following primary EBV infection. We show that, both immunocompetent and immunosuppressed animals were readily susceptible to EBV infection. However, immunosuppressed animals showed marked splenomegaly and widespread infection. Following EBV infection, the virus primarily targeted naïve IgM+, CD20+, CD21+ and CD79a+ B cells. Infected cells expressed varying sets of viral latent/lytic gene products. Notably, co-expression of latent and lytic proteins in the same cell was not observed. Infected cells in type 0/1 latency (EBERs+), were small and proliferating (Ki67+). By contrast, cells in type 2/3 latency (LMP1+), were large, non-proliferating (Ki-67-) and p53+. Although infected B-cells were widely present in splenic follicles, they did not express germinal center marker, BCL-6. Taken together, this study shows for the first time, some of the early events following primary EBV infection.


Asunto(s)
Infecciones por Virus de Epstein-Barr/inmunología , Centro Germinal/inmunología , Bazo/inmunología , Animales , Antígenos CD20/metabolismo , Linfocitos B/inmunología , Linfocitos B/virología , Antígenos CD79/metabolismo , Infecciones por Virus de Epstein-Barr/patología , Centro Germinal/virología , Inmunoglobulina M/inmunología , Antígeno Ki-67/metabolismo , Proteínas Proto-Oncogénicas c-bcl-6/metabolismo , Conejos , Receptores de Complemento 3d/metabolismo , Bazo/patología , Bazo/virología , Proteína p53 Supresora de Tumor/metabolismo
9.
Front Immunol ; 12: 738123, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34650561

RESUMEN

The diversity of B cell subsets and their contribution to vaccine-induced immunity in humans are not well elucidated but hold important implications for rational vaccine design. Prior studies demonstrate that B cell subsets distinguished by immunoglobulin (Ig) isotype expression exhibit divergent activation-induced fates. Here, the antigen-specific B cell response to tetanus toxoid (TTd) booster vaccination was examined in healthy adults, using a dual-TTd tetramer staining flow cytometry protocol. Unsupervised analyses of the data revealed that prior to vaccination, IgM-expressing CD27+ B cells accounted for the majority of TTd-binding B cells. 7 days following vaccination, there was an acute expansion of TTd-binding plasmablasts (PB) predominantly expressing IgG, and a minority expressing IgA or IgM. Frequencies of all PB subsets returned to baseline at days 14 and 21. TTd-binding IgG+ and IgA+ memory B cells (MBC) exhibited a steady and delayed maximal expansion compared to PB, peaking in frequencies at day 14. In contrast, the number of TTd-binding IgM+IgD+CD27+ B cells and IgM-only CD27+ B cells remain unchanged following vaccination. To examine TTd-binding capacity of IgG+ MBC and IgM+IgD+CD27+ B cells, surface TTd-tetramer was normalised to expression of the B cell receptor-associated CD79b subunit. CD79b-normalised TTd binding increased in IgG+ MBC, but remained unchanged in IgM+IgD+CD27+ B cells, and correlated with the functional affinity index of plasma TTd-specific IgG antibodies, following vaccination. Finally, frequencies of activated (PD-1+ICOS+) circulating follicular helper T cells (cTFH), particularly of the CXCR3-CCR6- cTFH2 cell phenotype, at their peak expansion, strongly predicted antigen-binding capacity of IgG+ MBC. These data highlight the phenotypic and functional diversity of the B cell memory compartment, in their temporal kinetics, antigen-binding capacities and association with cTFH cells, and are important parameters for consideration in assessing vaccine-induced immune responses.


Asunto(s)
Vacuna contra Difteria y Tétanos/administración & dosificación , Inmunización Secundaria , Inmunoglobulinas/sangre , Memoria Inmunológica/efectos de los fármacos , Células B de Memoria/efectos de los fármacos , Toxina Tetánica/administración & dosificación , Antígenos CD79/metabolismo , Vacuna contra Difteria y Tétanos/efectos adversos , Vacuna contra Difteria y Tétanos/inmunología , Voluntarios Sanos , Humanos , Proteína Coestimuladora de Linfocitos T Inducibles/metabolismo , Células B de Memoria/inmunología , Células B de Memoria/metabolismo , Fenotipo , Receptor de Muerte Celular Programada 1/metabolismo , Células T Auxiliares Foliculares/inmunología , Células T Auxiliares Foliculares/metabolismo , Toxina Tetánica/efectos adversos , Toxina Tetánica/inmunología , Miembro 7 de la Superfamilia de Receptores de Factores de Necrosis Tumoral/metabolismo
10.
Eur J Immunol ; 51(9): 2251-2265, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34323286

RESUMEN

Bruton's tyrosine kinase (Btk) is a crucial signaling molecule in BCR signaling and a key regulator of B- cell differentiation and function. Btk inhibition has shown impressive clinical efficacy in various B-cell malignancies. However, it remains unknown whether inhibition additionally induces changes in BCR signaling due to feedback mechanisms, a phenomenon referred to as BCR rewiring. In this report, we studied the impact of Btk activity on major components of the BCR signaling pathway in mice. As expected, NF-κB and Akt/S6 signaling was decreased in Btk-deficient B cells. Unexpectedly, phosphorylation of several proximal signaling molecules, including CD79a, Syk, and PI3K, as well as the key Btk-effector PLCγ2 and the more downstream kinase Erk, were significantly increased. This pattern of BCR rewiring was essentially opposite in B cells from transgenic mice overexpressing Btk. Importantly, prolonged Btk inhibitor treatment of WT mice or mice engrafted with leukemic B cells also resulted in increased phosho-CD79a and phospho-PLCγ2 in B cells. Our findings show that Btk enzymatic function determines phosphorylation of proximal and distal BCR signaling molecules in B cells. We conclude that Btk inhibitor treatment results in rewiring of BCR signaling, which may affect both malignant and healthy B cells.


Asunto(s)
Agammaglobulinemia Tirosina Quinasa/antagonistas & inhibidores , Linfocitos B/inmunología , Antígenos CD79/metabolismo , Fosfolipasa C gamma/metabolismo , Receptores de Antígenos de Linfocitos B/metabolismo , Agammaglobulinemia Tirosina Quinasa/genética , Animales , Antineoplásicos/farmacología , Linfocitos B/citología , Benzamidas/farmacología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Inmunoglobulina M/inmunología , Linfoma de Células B/patología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , FN-kappa B/metabolismo , Fosfatidilinositol 3-Quinasas/metabolismo , Fosforilación/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Pirazinas/farmacología , Transducción de Señal/inmunología , Quinasa Syk/metabolismo
11.
Mol Ther ; 29(9): 2677-2690, 2021 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-33940156

RESUMEN

Adoptively transferred CD19 chimeric antigen receptor (CAR) T cells have led to impressive clinical outcomes in B cell malignancies. Beyond induction of remission, the persistence of CAR-T cells is required to prevent relapse and provide long-term disease control. To improve CAR-T cell function and persistence, we developed a composite co-stimulatory domain of a B cell signaling moiety, CD79A/CD40, to induce a nuclear translocating signal, NF-κB, to synergize with other T cell signals and improve CAR-T cell function. CD79A/CD40 incorporating CD19CAR-T cells (CD19.79a.40z) exhibited higher NF-κB and p38 activity upon CD19 antigen exposure compared with the CD28 or 4-1BB incorporating CD19CAR-T cells (CD19.28z and CD19.BBz). Notably, we found that CD19.79a.40z CAR-T cells continued to suppress CD19+ target cells throughout the co-culture assay, whereas a tendency for tumor growth was observed with CD19.28z CAR-T cells. Moreover, CD19.79a.40z CAR-T cells exhibited robust T cell proliferation after culturing with CD19+ target cells, regardless of exogenous interleukin-2. In terms of in vivo efficiency, CD19.79a.40z demonstrated superior anti-tumor activity and in vivo CAR-T cell proliferation compared with CD19.28z and CD19.BBz CD19CAR-T cells in Raji-inoculated mice. Our data demonstrate that the CD79A/CD40 co-stimulatory domain endows CAR-T cells with enhanced proliferative capacity and improved anti-tumor efficacy in a murine model.


Asunto(s)
Antígenos CD19/inmunología , Antígenos CD40/metabolismo , Antígenos CD79/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/terapia , Receptores Quiméricos de Antígenos/metabolismo , Animales , Línea Celular Tumoral , Proliferación Celular , Técnicas de Cocultivo , Humanos , Inmunoterapia Adoptiva , Células K562 , Activación de Linfocitos , Ratones , FN-kappa B/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/inmunología , Resultado del Tratamiento , Ensayos Antitumor por Modelo de Xenoinjerto
12.
J Biol Chem ; 296: 100465, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33639170

RESUMEN

TRAF3 has diverse signaling functions, which vary by cell type. Uniquely in B lymphocytes, TRAF3 inhibits homeostatic survival. Highlighting the role of TRAF3 as a tumor suppressor, loss-of-function TRAF3 mutations are associated with human B-cell malignancies, while B-cell-specific deletion of TRAF3 in mice leads to autoimmunity and lymphoma development. The role of TRAF3 in inhibiting noncanonical NF-κB activation, CD40 and BAFF-R signaling to B cells is well documented. In contrast, TRAF3 enhances many T-cell effector functions, through associating with and enhancing signaling by the T-cell receptor (TCR)-CD28 complex. The present study was designed to determine the role of TRAF3 in signaling via the B-cell antigen receptor (BCR). The BCR is crucial for antigen recognition, survival, proliferation, and antibody production, and defects in BCR signaling can promote abnormal survival of malignant B cells. Here, we show that TRAF3 is associated with both CD79B and the BCR-activated kinases Syk and Btk following BCR stimulation. BCR-induced phosphorylation of Syk and additional downstream kinases was increased in TRAF3-/- B cells, with regulation observed in both follicular and marginal zone B-cell subsets. BCR stimulation of TRAF3-/- B cells resulted in increased surface expression of MHC-II, CD80, and CD86 molecules. Interestingly, increased survival of TRAF3-/- primary B cells was resistant to inhibition of Btk, while TRAF3-deficient malignant B-cell lines showed enhanced sensitivity. TRAF3 serves to restrain normal and malignant BCR signaling, with important implications for its role in normal B-cell biology and abnormal survival of malignant B cells.


Asunto(s)
Receptores de Antígenos de Linfocitos B/metabolismo , Factor 3 Asociado a Receptor de TNF/metabolismo , Agammaglobulinemia Tirosina Quinasa/metabolismo , Animales , Linfocitos B/inmunología , Linfocitos B/metabolismo , Antígenos CD79/metabolismo , Femenino , Masculino , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Fosforilación , Receptores de Antígenos de Linfocitos B/genética , Transducción de Señal/genética , Quinasa Syk/metabolismo , Linfocitos T/metabolismo , Factor 2 Asociado a Receptor de TNF/metabolismo , Factor 3 Asociado a Receptor de TNF/genética
13.
Commun Biol ; 4(1): 73, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-33452446

RESUMEN

Central nervous system (CNS) involvement remains a challenge in the diagnosis and treatment of acute lymphoblastic leukemia (ALL). In this study, we identify CD79a (also known as Igα), a signaling component of the preB cell receptor (preBCR), to be associated with CNS-infiltration and -relapse in B-cell precursor (BCP)-ALL patients. Furthermore, we show that downregulation of CD79a hampers the engraftment of leukemia cells in different murine xenograft models, particularly in the CNS.


Asunto(s)
Antígenos CD79/metabolismo , Neoplasias del Sistema Nervioso Central/metabolismo , Leucemia-Linfoma Linfoblástico de Células Precursoras B/metabolismo , Familia-src Quinasas/metabolismo , Animales , Línea Celular Tumoral , Humanos , Ratones , Ensayos Antitumor por Modelo de Xenoinjerto
15.
Target Oncol ; 15(3): 365-375, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32495161

RESUMEN

BACKGROUND: Although chimeric antigen receptor (CAR) T-cell therapy targeting antigens expressed in refractory and relapsed non-Hodgkin B-cell lymphoma, such as CD19 and CD22, has achieved encouraging clinical effects, some patients fail to attain remission, or relapse after CAR T-cell therapy, which has been ascribed to the loss of the target antigens. OBJECTIVE: To evaluate CD79b as an alternative target for CAR T-cell B-cell lymphoma therapy. PATIENT AND METHODS: The expression of CD79b in different B-cell lymphomas was determined. Anti-CD79b CAR T-cells expressing one of two different CARs were generated, and a series of in vitro and in vivo experiments were conducted to assess the CAR T-cell function. RESULTS: We found that CD79b was extensively expressed on the tumor cells of patients with various types of lymphoma regardless of stage, subtype, and cytogenetic and molecular features. Anti-CD79b CAR T-cells were highly specific and effective for the treatment of B-cell lymphomas. CONCLUSIONS: Our data indicate that CD79b could be used as a target for CAR T-cell therapy of B-cell lymphomas, and further clinical development is warranted.


Asunto(s)
Antígenos CD79/metabolismo , Linfoma de Células B/genética , Receptores Quiméricos de Antígenos/metabolismo , Animales , Línea Celular Tumoral , Femenino , Humanos , Ratones , Transfección
16.
J Immunol ; 204(10): 2852-2863, 2020 05 15.
Artículo en Inglés | MEDLINE | ID: mdl-32253241

RESUMEN

BCR signaling, involving phosphorylation of various downstream molecules, including kinases, lipases, and linkers, is crucial for B cell selection, survival, proliferation, and differentiation. Phosphoflow cytometry (phosphoflow) is a single-cell-based technique to measure phosphorylated intracellular proteins, providing a more quantitative read-out than Western blotting. Recent advances in phosphoflow basically allow simultaneous analysis of protein phosphorylation in B cell (sub)populations, without prior cell sorting. However, fixation and permeabilization procedures required for phosphoflow often affect cell surface epitopes or mAb conjugates, precluding the evaluation of the phosphorylation status of signaling proteins across different B cell subpopulations present in a single sample. In this study, we report a versatile phosphoflow protocol allowing extensive staining of B cell subpopulations in human peripheral blood or various anatomical compartments in the mouse, starting from freshly isolated or frozen cell suspensions. Both human and mouse B cell subpopulations showed different basal and BCR stimulation-induced phosphorylation levels of downstream signaling proteins. For example, peritoneal B-1 cells and splenic marginal zone B cells exhibited significantly increased basal (ex vivo) signaling and increased responsiveness to in vitro BCR stimulation compared with peritoneal B-2 cells and splenic follicular B cells, respectively. In addition, whereas stimulation with anti-IgM or anti-Igκ L chain Abs resulted in strong pCD79a and pPLCγ2 signals, IgD stimulation only induced CD79a but not pPLCγ2 phosphorylation. In summary, the protocol is user friendly and quantifies BCR-mediated phosphorylation with high sensitivity at the single-cell level, in combination with extensive staining to identify individual B cell development and differentiation stages.


Asunto(s)
Subgrupos de Linfocitos B/fisiología , Linfocitos B/fisiología , Citometría de Flujo/métodos , Receptores de Antígenos de Linfocitos B/metabolismo , Animales , Antígenos CD79/metabolismo , Diferenciación Celular , Células Cultivadas , Humanos , Inmunoglobulina D/metabolismo , Inmunoglobulina M/metabolismo , Activación de Linfocitos , Ratones , Ratones Endogámicos C57BL , Fosfolipasa C gamma/metabolismo , Fosforilación , Transducción de Señal , Análisis de la Célula Individual
17.
Cancer Genet ; 240: 40-44, 2020 01.
Artículo en Inglés | MEDLINE | ID: mdl-31739126

RESUMEN

T-cell acute lymphoblastic leukemia/lymphoma (T-ALL/LBL) is usually diagnosed based on the presence of immature lymphoid marker terminal deoxynucleotidyl transferase (TdT), and T-cell specific markers, specifically CD3, by immunohistochemistry (IHC) staining on bone marrow and/or extramedullary tissue. We present a novel, TdT and CD3 negative, aggressive early T-cell precursor LBL (ETP-LBL) initially misdiagnosed as a high grade B-cell lymphoma due to expression of CD79a and the erroneous detection of BCL2/IGH fusion. The patient was eventually evaluated using molecular diagnostic techniques, including fluorescence in situ hybridization (FISH) and next generation sequencing (NGS) assays that demonstrated PICALM-MLLT10 fusion and a NOTCH1 mutation in the absence of BCL2/IGH fusion. The use of NGS, specifically mate-pair sequencing (MPseq), subsequently confirmed an in-frame PICALM-MLLT10 fusion. Our retrospective analysis showed that PICALM-MLLT10 fusion has no association with CD3/TdT negativity, as 6/49 T-ALL/LBL cases from Mayo Clinic database (01/1998-09/2018), including this case, were noted to have PICALM-MLLT10 fusion; however, none of the other cases were associated with CD3/TdT negativity. We emphasize the importance of a comprehensive hematopathologic evaluation including multiple molecular studies for the appropriate interrogation and classification of a difficult acute leukemia diagnosis, and to prevent potential diagnostic errors of clinical significance.


Asunto(s)
Linfocitos B/inmunología , Antígenos CD79/metabolismo , Neoplasias del Mediastino/diagnóstico , Proteínas de Fusión Oncogénica/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/diagnóstico , Adulto , Linfocitos B/metabolismo , Biopsia , Antígenos CD79/análisis , Antígenos CD79/inmunología , Errores Diagnósticos , Humanos , Linfoma de Células B/sangre , Linfoma de Células B/diagnóstico , Linfoma de Células B/genética , Linfoma de Células B/inmunología , Masculino , Neoplasias del Mediastino/sangre , Neoplasias del Mediastino/genética , Neoplasias del Mediastino/inmunología , Mediastino/diagnóstico por imagen , Mediastino/patología , Leucemia-Linfoma Linfoblástico de Células T Precursoras/sangre , Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Leucemia-Linfoma Linfoblástico de Células T Precursoras/inmunología , Tomografía Computarizada por Rayos X
18.
Pathol Int ; 69(12): 697-705, 2019 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-31872533

RESUMEN

Anaplastic variant (av) of diffuse large B-cell lymphoma (DLBCL) is morphologically defined in the 2017 World Health Organization classification, but still an enigmatic disease in its clinicopathologic distinctiveness, posing the differential diagnostic problem from gray zone lymphoma (GZL) and classic Hodgkin lymphoma (cHL). Thirty-one cases previously diagnosed as avDLBCL were reassessed. Of these, 27 (87%) and 4 (13%) were node-based and extranodal diseases, respectively. They were further reclassified into nodal avDLBCL (n = 18), nodal CD30+ DLBCL with T-cell/histiocyte-rich large B-cell lymphoma-like features (CD30+ DLBCL-THRLBCL) (n = 6), GZL with features intermediate between DLBCL and cHL (n = 3) and CD30+ extranodal DLBCL, NOS (n = 4). The nodal avDLBCL cases had a sheet-like proliferation of large cells and/or Hodgkin/Reed-Sternberg (HRS)-like cells in 12 (67%) notably with a sinusoidal pattern in 16 (89%). They showed an expression of CD20 and/or CD79a in all and CD30 in 15 of 18. All of them were negative for PD-L1 on tumor cells, although HRS-like cells showed negativity or partial loss of other B-cell markers to varying degrees. The present study highlighted the distinctiveness of the nodal avDLBCL with sinusoidal pattern, but without neoplastic PD-L1 expression, which provide refined diagnostic criteria for a more precise pathologic and clinical characterization of this disease.


Asunto(s)
Biomarcadores de Tumor/metabolismo , Enfermedad de Hodgkin/patología , Linfoma de Células B Grandes Difuso/patología , Anciano , Anciano de 80 o más Años , Antígenos CD20/metabolismo , Antígenos CD79/metabolismo , Capilares/metabolismo , Capilares/patología , Femenino , Enfermedad de Hodgkin/diagnóstico , Enfermedad de Hodgkin/metabolismo , Humanos , Antígeno Ki-1/metabolismo , Linfoma de Células B Grandes Difuso/diagnóstico , Linfoma de Células B Grandes Difuso/metabolismo , Masculino , Persona de Mediana Edad
19.
J Vet Sci ; 20(2): e11, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30944534

RESUMEN

Mammary lesions in sows can prevent suckling piglets from consuming colostrum that provides fundamental nutrients and protective immunity. Although mammary gross lesions are frequently found in sows at farms or slaughterhouses, with the exception of mastitis, they have received little research attention. In this study, we investigated mammary lesions observed in South Korean sows between 2015 and 2016. Mammary tissue samples of 82 sows showing gross lesions during meat inspection were histologically classified and immunohistochemical analysis was conducted to assess the expression of estrogen receptor (ER)-α, ER-ß, and progesterone receptor (PR) for mammary hyperplastic lesions as well as that of cluster of differentiation (CD) 3, CD79a, interleukin (IL)-1α, IL-1ß, IL-6, and IL-8 for mastitis. Furthermore, 20 swab samples were cultured, and the isolated bacteria were identified using polymerase chain reactions for 16S ribosomal RNA genes. The lesions were classified as hyperplasia, mastitis, or hyperplasia with mastitis. Immunohistochemistry results revealed that there was neither expression of ER-α nor of ER-ß, but all examined hyperplastic samples expressed PR. In addition, there was a significant correlation between CD3 and IL-1ß expressions, as well as between IL-1ß and IL-6 expressions. Regarding the identity of the isolated bacteria, Pseudomonas spp. were most frequently detected. The results of this study have revealed the incidence and characteristics of porcine mammary lesions.


Asunto(s)
Enfermedades de la Mama/veterinaria , Citocinas/metabolismo , Glándulas Mamarias Animales/patología , Receptores de Estrógenos/metabolismo , Enfermedades de los Porcinos/patología , Mataderos , Animales , Enfermedades de la Mama/metabolismo , Enfermedades de la Mama/microbiología , Enfermedades de la Mama/patología , Complejo CD3/metabolismo , Antígenos CD79/metabolismo , Receptor alfa de Estrógeno/metabolismo , Receptor beta de Estrógeno/metabolismo , Femenino , Interleucina-1alfa/metabolismo , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Glándulas Mamarias Animales/metabolismo , Glándulas Mamarias Animales/microbiología , Mastitis/metabolismo , Mastitis/microbiología , Mastitis/patología , Mastitis/veterinaria , Pseudomonas , Receptores de Progesterona/metabolismo , Porcinos , Enfermedades de los Porcinos/clasificación , Enfermedades de los Porcinos/metabolismo , Enfermedades de los Porcinos/microbiología
20.
World Neurosurg ; 125: 339-342, 2019 05.
Artículo en Inglés | MEDLINE | ID: mdl-30797915

RESUMEN

BACKGROUND: We describe a patient affected by a T-cell primary central nervous system lymphoma (PCNSL) with highly aberrant specific B-cell markers (CD79a and CD20). An unusual imaging presentation leads us to misdiagnose this lesion for a meningioma and perform surgical resection. CASE DESCRIPTION: We think that this infrequent anatomic presentation might be due to the aberrant specific B-cell markers (CD79a and CD20) genotype expression. We believe this case to be relevant in order to appreciate the diagnosis of cerebral lymphomas according to various presentations. We wonder whether it was not the aberrant genotype that contributed to this quirky presentation and ultimately if surgery in PCNSL should not be discussed? CONCLUSIONS: Furthermore, this case calls attention to the complexity of lineage assignment, imaging diagnosis, and treatment strategy in PCNSL.


Asunto(s)
Neoplasias del Sistema Nervioso Central/diagnóstico , Linfoma de Células T/diagnóstico , Meningioma/diagnóstico , Anciano , Antígenos CD20/metabolismo , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Biomarcadores de Tumor/metabolismo , Antígenos CD79/metabolismo , Neoplasias del Sistema Nervioso Central/tratamiento farmacológico , Neoplasias del Sistema Nervioso Central/cirugía , Diagnóstico Diferencial , Errores Diagnósticos , Femenino , Humanos , Linfoma de Células T/tratamiento farmacológico , Linfoma de Células T/cirugía , Imagen por Resonancia Magnética , Neoplasias Meníngeas/diagnóstico , Neoplasias Meníngeas/cirugía , Meningioma/cirugía , Imagen Multimodal , Tomografía de Emisión de Positrones , Tomografía Computarizada por Rayos X
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